In general, a connector as shown in FIG. 9 for being electrically connected to a counter part connector (receptacle connector) that is fixed to a circuit board such as a mother board on server's side has been known. This connector is a plug connector as a transceiver module complying with MSA (Multi Source Agreement) on SFP (Small Form-Factor Pluggable). A connector complying with this specification is capable of transmitting signal at a rate of several Gbps (bits/s), for example at a rate of 2-4 Gbps, to a hard disk or a storage device such as RAID (Redundant Arrays of Independent Disks) or a CD-ROM.
In MSA, specification is provided on mechanical interface part of a system including a plug connector, a receptacle connector and a circuit board on server's side for receiving external signal. With regard to a plug connector, specifications are provided on shape, dimensions, dimensional tolerances and the like, and with regard to a PCB (Printed Circuit Board) contained in the cavity, specification on contact lay-out and the like are provided. With regard to a receptacle connector, specifications are provided on shape, dimensions, and dimensional tolerances as well as contact lay-out corresponding to the contacts of a plug connector are provided. With regard to a circuit board on server's side, specifications on contact lay-out on ASIC side and on BEZEL side are provided. In addition, specification on dimensions of a cage (receptacle) which functions also as a noise shield, and on insertion force and retaining force between connectors electrically connected to each other, are provided.
FIG. 9 is a view showing a plug connector 50 upside down for the sake of convenience. The connector 50 comprises a connector housing 51 and a PCB 55 which is contained in the cavity 58 of the connector housing 51 and has contacts 57 with contacting surface exposed at one end. The connector housing 51 comprises an upper shell and a lower shell 52, 53 formed of electro-conductive material. The lower shell 53, which is positioned on upper side in the Figure for convenience, has an opening 54 on the side to be fitted to, for example, a receptacle connector. PCB 55 comprises an insulating substrate 56 which has specified circuit pattern formed thereon and has contacts 57 with contacting surface exposed to outside and has unshown cable connection section on opposite side to the contacts 57. PCB 55 is contained in the cavity 58 of the connector housing 51 except for the end having the contacts 57.
A receptacle connector 60 shown in FIG. 10 comprises a connector housing 61 having a fitting section 62, and terminals 63, 64 disposed on upper and lower sides of the fitting section 62. The fitting section 62 is formed in the shape of frame adapted to have PCB of the plug connector inserted therein. The terminals 63, 64 are formed by press punching from electro-conductive material in one unit with the connector housing 61 formed by resin molding. The parts of the terminals exposed in the fitting section 62 are contacts 63a, 64a and are positioned so as to be electrically connected to the contacts formed on the front and rear sides of PCB.
Another example of conventional plug connector of this type is disclosed in U.S. Pat. No. 6,524,134. A plug connector disclosed in this Patent Document has generally same specification as the plug connector shown in FIG. 9 except that it comprises an adapter and a photoelectric conversion element interconnected to an optical connector at the rear end of the connector housing.